7,381 research outputs found

    Статичні змішувачі в циркуляційних системах промивальної рідини бурових установок

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    The work of three static mixer designs in flushing fluid circulation systems of drilling rigs was studied taking into account the basic parameters of drilling mud. Modelling was carried out, and parametric slurry fields were obtained in the pipe work area, that is in a static mixer installation site and in the area of pipeline behind it. The following models were obtained: velocity fields, vorticity fields, turbulence intensity fields, scale turbulence fields along the travel path. Graphs of the parameters changes regarding the tube axis were plotted. The comparative analysis of patterns and curves was carried out. The rational design of static mixer for obtaining of optimum mud mixing technology features is grounded.Досліджено роботу трьох конструкцій статичного змішувача в циркуляційній системі промивальної рідини бурових установок, ураховуючи основні параметри бурового розчину. Виконано моделювання та отримано параметричні поля гідросуміші у робочій зоні труби, а саме в місці установки статичного змішувача і в зоні трубопроводу за ним. Отримано моделі: поля швидкостей, поля завихреності, поля інтенсивності турбулентності, поля масштабу турбулентностей по довжині шляху перемішування. Побудовано графіки зміни досліджуваних параметрів відносно осі труби. Виконано порівняльний аналіз моделей та кривих. Обґрунтовано раціональну конструкцію статичного змішувача для отримання оптимальних технологічних характеристик перемішування бурового розчину

    Applicability of point dipoles approximation to all-dielectric metamaterials

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    All-dielectric metamaterials consisting of high-dielectric inclusions in a low-dielectric matrix are considered as a low-loss alternative to resonant metal-based metamaterials. In this contribution we investigate the applicability of the point electric and magnetic dipoles approximation to dielectric meta-atoms on the example of a dielectric ring metamaterial. Despite the large electrical size of high-dielectric meta-atoms, the dipole approximation allows for accurate prediction of the metamaterials properties for the rings with diameters up to ~0.8 of the lattice constant. The results provide important guidelines for design and optimization of all-dielectric metamaterials.Comment: 10 pages, 5 fugures, submitted to Physical Review

    THE OUTLOOK ON THE E-COMMERCE IN RUSSIA IN TERMS OF DIGITAL SINGLE MARKET STRATEGY DEVELOPMENT IN EUROPE: ECONOMIC AND LEGAL ASPECTS

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    The aim of the research is to emphasize the importance of online E-commerce on a worldwide scale in the context of the benefi ts it provides to the national governments. Special attention is paid to the key E-market trends in Russia and European Community with a brief overview of the statistics and analysis data, which proves the necessity for its future development. However, the potential development of e-market in Russia has certain restrictions, connected with the current economic downtown, lack of legal provision and general consumer’s distrust to online transactions. Authors dwell upon the possible ways of overcoming these urgent obstacles according to the European policy of bringing down barriers to unlock online opportunities, which is called the Digital Single Market (DSM). To do that, the paper explores the benefi ts of the DSM Strategy’s introduction in Europe and the reasons whether it could be implemented into the Russia’s frontiers or not. Finally, authors reckon that despite the fact that the several legislative improvements relating to electronic market has been introduced in recent years, there are several efficient suggestions to our government to scrutinize in order to achieve high rates of online sales, bring the economy up and enforce cross-border cooperation

    New records of lichens from the Zeysky Nature Reserve (Amur Region, Russia)

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    The lichen biota of the Zeysky Nature Reserve (southern Russian Far East) was studied in the course of geobotanical expedition. In total 36 species of lichens and one lichenicolous fungus are reported for the first time for the reserve. Among them 19 are new to the Amur Region. Parmelia asiatica is reported for the first time for the southern Russian Far East, Cladonia norvegica – for the Asian part of Russia, Tuckermannopsis gilva – for Russia, Melanohalea laciniatula – for Asia. Four species are included in the Red Data Book of Russian Federation.
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